1 .TH XARGS 1 \" -*- nroff -*-
3 xargs \- build and execute command lines from standard input
6 [\-0prtx] [\-E[eof-str]] [\-e[eof-str]] [\-\-eof[=eof-str]] [\-\-null]
7 [\-I[replace-str]] [\-i[replace-str]] [\-\-replace[=replace-str]]
8 [\-l[max-lines]] [\-L[max-lines]] [\-\-max\-lines[=max-lines]] [\-n max-args] [\-\-max\-args=max-args]
9 [\-s max-chars] [\-\-max\-chars=max-chars] [\-P max-procs] [\-\-max\-procs=max-procs]
10 [\-\-interactive] [\-\-verbose] [\-\-exit]
11 [\-\-no\-run\-if\-empty] [\-\-arg\-file=file] [\-\-version] [\-\-help]
12 [command [initial-arguments]]
15 documents the GNU version of
18 reads items from the standard input, delimited by blanks (which can be
19 protected with double or single quotes or a backslash) or newlines,
22 (default is /bin/echo) one or more times with any
24 followed by items read from standard input. Blank lines on the
25 standard input are ignored.
27 Because Unix filenames can contain blanks and newlines, this default
28 behaviour is often problematic; filenames containing blanks
29 and/or newlines are incorrectly processed by
31 In these situations it is better to use the `\-0' option, which
32 prevents such problems. When using this option you will need to
33 ensure that the program which produces the input for
35 also uses a null character as a separator. If that program is
38 for example, the `\-print0' option does this for you.
40 If any invocation of the command exits with a status of 255,
42 will stop immediately without reading any firther input. An error
43 message is issued on stderr when this happens.
46 .I "\-\-arg\-file=file, \-a file"
49 instead of standard input. If you use this option, stdin remains
50 unchanged when commands are run. Otherwise, stdin is redirected
56 Input items are terminated by a null character instead of by
57 whitespace, and the quotes and backslash are not special (every
58 character is taken literally). Disables the end of file string, which
59 is treated like any other argument. Useful when input items might
60 contain white space, quote marks, or backslashes. The GNU find
61 \-print0 option produces input suitable for this mode.
63 .I "\-\-eof[=eof-str], \-E[eof-str]"
64 Set the end of file string to \fIeof-str\fR. If the end of file
65 string occurs as a line of input, the rest of the input is ignored.
66 If \fIeof-str\fR is omitted, there is no end of file string. If this
67 option is not given, no end of file string is used.
70 This option is a synonym for the `\-E' option. Use `\-E' instead,
71 because it is POSIX compliant while this option is not.
74 Print a summary of the options to
78 .I "\-\-replace[=replace-str], \-i[replace-str]"
79 Replace occurences of \fIreplace-str\fR in the initial-arguments with
80 names read from standard input.
81 Also, unquoted blanks do not terminate input items; instead the
82 separator is the newline character.
83 If \fIreplace-str\fR is omitted, it
84 defaults to "{}" (like for `find \-exec'). Implies \fI\-x\fP and
87 .I "\-\-max\-lines[=max-lines], \-L[max-lines]"
88 Use at most \fImax-lines\fR nonblank input lines per command line;
89 \fImax-lines\fR defaults to 1 if omitted. Trailing blanks cause an
90 input line to be logically continued on the next input line. Implies
94 Deprecated; non-POSIX-compliant synonym for the
98 .I "\-\-max\-args=max-args, \-n max-args"
99 Use at most \fImax-args\fR arguments per command line. Fewer than
100 \fImax-args\fR arguments will be used if the size (see the \-s option)
101 is exceeded, unless the \-x option is given, in which case \fBxargs\fR
104 .I "\-\-interactive, \-p"
105 Prompt the user about whether to run each command line and read a line
106 from the terminal. Only run the command line if the response starts
107 with `y' or `Y'. Implies \fI\-t\fR.
109 .I "\-\-no\-run\-if\-empty, \-r"
110 If the standard input does not contain any nonblanks, do not run the
111 command. Normally, the command is run once even if there is no input.
113 .I "\-\-max\-chars=max-chars, \-s max-chars"
114 Use at most \fImax-chars\fR characters per command line, including the
115 command and initial-arguments and the terminating nulls at the ends of
116 the argument strings. The default is 131072 characters, not including
117 the size of the environment variables (which are provided for
118 separately so that it doesn't matter if your environment variables
119 take up more than 131072 bytes). The operating system places limits
120 on the values that you can usefully specify, and if you exceed these a
121 warning message is printed and the value actually used is set to the
122 appropriate upper or lower limit.
124 .I "\-\-verbose, \-t"
125 Print the command line on the standard error output before executing
129 Print the version number of
134 Exit if the size (see the \fI\-s\fR option) is exceeded.
136 .I "\-\-max\-procs=max-procs, \-P max-procs"
137 Run up to \fImax-procs\fR processes at a time; the default is 1. If
138 \fImax-procs\fR is 0, \fBxargs\fR will run as many processes as
139 possible at a time. Use the \fI\-n\fR option with \fI\-P\fR;
140 otherwise chances are that only one exec will be done.
143 .B find /tmp \-name core \-type f \-print | xargs /bin/rm \-f
148 in or below the directory
150 and delete them. Note that this will work incorrectly if there are
151 any filenames containing newlines or spaces.
153 .B find /tmp \-name core \-type f \-print0 | xargs \-0 /bin/rm \-f
158 in or below the directory
160 and delete them, processing filenames in such a way that file or
161 directory names containing spaces or newlines are correctly handled.
164 .B cut \-d: \-f1 < /etc/passwd | sort | xargs echo
167 Generates a compact listing of all the users on the system.
170 exits with the following status:
173 123 if any invocation of the command exited with status 1-125
174 124 if the command exited with status 255
175 125 if the command is killed by a signal
176 126 if the command cannot be run
177 127 if the command is not found
178 1 if some other error occurred.
181 Exit codes greater than 128 are used by the shell to indicate that
182 a program died due to a fatal signal.
183 .SH "STANDARDS CONFORMANCE"
184 As of GNU xargs version 4.2.9, the default behaviour of
186 is not to have a logical end-of-file marker. POSIX (IEEE Std 1003.1,
187 2004 Edition) allows this.
190 \fBfind\fP(1), \fBlocate\fP(1), \fBlocatedb\fP(5), \fBupdatedb\fP(1),
191 \fBFinding Files\fP (on-line in Info, or printed)
194 When you use the \-i option, each line read from the input is buffered
195 internally. This means that there is an upper limit on the length
198 will accept when used with the \-i option. To work around this
199 limitation, you can use the \-s option to increase the amount of
202 uses, and you can also use an extra invocation of
204 to ensure that very long lines do not occur.
207 .B somecommand | xargs \-s 50000 echo | xargs \-i \-s 100000 rm '{}'
209 Here, the first invocation of
211 has no input line length limit
212 because it doesn't use the \-i option. The second invocation of
214 does have such a limit, but we have ensured that the it never encounters
215 a line which is longer than it can handle. This is not an ideal
216 solution. Instead, the \-i option should not impose a line length
217 limit, which is why this discussion appears in the BUGS section.
218 The problem doesn't occur with the output of
220 because it emits just one filename per line.
222 The best way to report a bug is to use the form at
223 http://savannah.gnu.org/bugs/?group=findutils.
224 The reason for this is that you will then be able to track progress in
225 fixing the problem. Other comments about \fBxargs\fP(1) and about
226 the findutils package in general can be sent to the
228 mailing list. To join the list, send email to
229 .IR bug\-findutils\-request@gnu.org .